[PATCH 18/47] KVM: SVM: cache nested intercepts

From: Avi Kivity
Date: Wed Aug 26 2009 - 06:31:11 EST


From: Joerg Roedel <joerg.roedel@xxxxxxx>

When the nested intercepts are cached we don't need to call
get_user_pages and/or map the nested vmcb on every nested #vmexit to
check who will handle the intercept.
Further this patch aligns the emulated svm behavior better to real
hardware.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
---
arch/x86/kvm/svm.c | 30 +++++++++++++++++++++++-------
1 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index fbadaa7..4426c63 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -80,6 +80,15 @@ struct nested_state {

/* gpa pointers to the real vectors */
u64 vmcb_msrpm;
+
+ /* cache for intercepts of the guest */
+ u16 intercept_cr_read;
+ u16 intercept_cr_write;
+ u16 intercept_dr_read;
+ u16 intercept_dr_write;
+ u32 intercept_exceptions;
+ u64 intercept;
+
};

struct vcpu_svm {
@@ -1452,7 +1461,6 @@ static int nested_svm_exit_handled_real(struct vcpu_svm *svm,
void *arg2,
void *opaque)
{
- struct vmcb *nested_vmcb = (struct vmcb *)arg1;
bool kvm_overrides = *(bool *)opaque;
u32 exit_code = svm->vmcb->control.exit_code;

@@ -1479,38 +1487,38 @@ static int nested_svm_exit_handled_real(struct vcpu_svm *svm,
switch (exit_code) {
case SVM_EXIT_READ_CR0 ... SVM_EXIT_READ_CR8: {
u32 cr_bits = 1 << (exit_code - SVM_EXIT_READ_CR0);
- if (nested_vmcb->control.intercept_cr_read & cr_bits)
+ if (svm->nested.intercept_cr_read & cr_bits)
return 1;
break;
}
case SVM_EXIT_WRITE_CR0 ... SVM_EXIT_WRITE_CR8: {
u32 cr_bits = 1 << (exit_code - SVM_EXIT_WRITE_CR0);
- if (nested_vmcb->control.intercept_cr_write & cr_bits)
+ if (svm->nested.intercept_cr_write & cr_bits)
return 1;
break;
}
case SVM_EXIT_READ_DR0 ... SVM_EXIT_READ_DR7: {
u32 dr_bits = 1 << (exit_code - SVM_EXIT_READ_DR0);
- if (nested_vmcb->control.intercept_dr_read & dr_bits)
+ if (svm->nested.intercept_dr_read & dr_bits)
return 1;
break;
}
case SVM_EXIT_WRITE_DR0 ... SVM_EXIT_WRITE_DR7: {
u32 dr_bits = 1 << (exit_code - SVM_EXIT_WRITE_DR0);
- if (nested_vmcb->control.intercept_dr_write & dr_bits)
+ if (svm->nested.intercept_dr_write & dr_bits)
return 1;
break;
}
case SVM_EXIT_EXCP_BASE ... SVM_EXIT_EXCP_BASE + 0x1f: {
u32 excp_bits = 1 << (exit_code - SVM_EXIT_EXCP_BASE);
- if (nested_vmcb->control.intercept_exceptions & excp_bits)
+ if (svm->nested.intercept_exceptions & excp_bits)
return 1;
break;
}
default: {
u64 exit_bits = 1ULL << (exit_code - SVM_EXIT_INTR);
nsvm_printk("exit code: 0x%x\n", exit_code);
- if (nested_vmcb->control.intercept & exit_bits)
+ if (svm->nested.intercept & exit_bits)
return 1;
}
}
@@ -1801,6 +1809,14 @@ static int nested_svm_vmrun(struct vcpu_svm *svm, void *arg1,

svm->nested.vmcb_msrpm = nested_vmcb->control.msrpm_base_pa;

+ /* cache intercepts */
+ svm->nested.intercept_cr_read = nested_vmcb->control.intercept_cr_read;
+ svm->nested.intercept_cr_write = nested_vmcb->control.intercept_cr_write;
+ svm->nested.intercept_dr_read = nested_vmcb->control.intercept_dr_read;
+ svm->nested.intercept_dr_write = nested_vmcb->control.intercept_dr_write;
+ svm->nested.intercept_exceptions = nested_vmcb->control.intercept_exceptions;
+ svm->nested.intercept = nested_vmcb->control.intercept;
+
force_new_asid(&svm->vcpu);
svm->vmcb->control.exit_int_info = nested_vmcb->control.exit_int_info;
svm->vmcb->control.exit_int_info_err = nested_vmcb->control.exit_int_info_err;
--
1.6.4.1

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